Many devices and methods have been arrived at for audiometric purposes for determining hearing acuity. Most of the methods and devices developed, however, have been lacking in providing for reliable and reproducible results or for accurately testing the hearing acuity of the subject being tested under the conditions which the subject normally encounters.
In the existing model, word recognition score estimations are standardized only to the intensity component of speech and often are limited to morpheme level analysis. The existing word recognition score estimation system depends on oral presentations of the stimuli by a clinician. The determination of basic hearing acuity with respect to, for example, the amplitude of a sound, such as a spoken word, which the subject can correctly identify, is not particularly difficult. However, a simple test of this nature fails to take into account important factors that determine actual hearing acuity of the subject under normal environmental conditions.
The existing tools for checking the benefit received from an augmented listening device, does not take into account the effect of background noise on the performance of the device despite it being one of the top priorities when it comes to choice of amplification.
In particular, conventional audiometer tests to determine hearing acuity does not take into account the background noises to which the subject is exposed when the acuity of the subjects hearing is most important, especially when the subject is engaged in his normal occupation. For example, a subject employed in a certain location in a factory will be exposed to certain types of background noise more or less continuously and it is under these particular conditions that the hearing acuity of the subject is important. Furthermore, each environment is accompanied by a relatively specific background noise at substantially constant sound level, and it is only in the presence of such noise that the hearing acuity of a subject can be reliably determined.